CXCL8 and rheumatic heart disease: Both Batzloff et al. [19] and Reynolds et al. [28], asmentioned earlier, assessed the safety of candidate vaccines in RHD rat models.They focused on J8 (derived from a cryptic epitope in the C3 repeat sequence ofGAS M protein), p*17 (from GAS M-protein epitopes), and K4S2 (from the interleukin-8 (IL-8)degrading S. pyogenes Cell-Envelope Proteinase [SpyCEP] epitope) [19, 28].